Almost every Quad Collector is aware of the many attempts at getting 4 channels of audio onto a vinyl LP. The early Matrix systems (RM, EV, DY) soon gave way to the more elaborate SQ and  QS systems from Columbia and Sansui, while JVC developed the CD-4 system which delivered true discrete performance. What many Quad Collectors don't know is that there was an additional "system", developed by DENON in Japan for reproducing a true 4 channel source on a vinyl disc, and those that are aware of the system actually know very little about it. There are many misconceptions surrounding UD-4. Hypothetical explanations abound, but there is little concrete information on the web to clarify and put to rest all of the speculation and false truths about this format.

Thanks to one of our members, we have the information on these few pages that actually describe and explain the process of UD-4. There were only a handful of LPs ever released in this format, and a listing of those titles can also be found below.

Anyone with additional info or documentation on UD-4 is welcomed to email us and we will be glad to incorporate that material into these pages.

Here are some of the QuadraphonicQuad resources on UD-4
 

UD-4 QUADRAPHONIC LP CHECKLIST RELEASED ON THE NIPPON-COLUMBIA (DENON) LABEL

SCANS OF THE UD-4 RELEASE OF "TUBULAR BELLS

HI-FI NEWS & RECORD REVIEW ARTICLE ON THE UD-4 SYSTEM

AUDIO ENGINEERING SOCIETY PAPER ON THE UD-4 SYSTEM (Scanned)

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